1. Field of the Invention.
The present invention relates to indicator devices and more particularly to fuel economy indicator devices for use with internal combustion engines.
2. Prior Art.
It is known to provide a vacuum gage connected to the induction manifold of an internal combustion engine wherein the manifold depression can be interpreted as an indication of fuel economy. Such devices often include an indicator needle, movable with respect to a dial for indicating the degree of manifold depression or relative fuel economy. Interpretation of such devices requires concentrated attention on the part of the engine operator which can be objectionable particularly where the engine is mounted in a motor vehicle.
It is also known to provide one or more electrical contact switches which open and close responsive to changes in manifold depression, the switches being connected to indicator lamps. These latter mentioned devices overcome the problem of concentrated attention on the part of the operator but are subject to the objection that the desired number of switch-lamp pairs are expensive, occupy too much space and may malfunction as a result of frequent switch actuation.